Is there natural vitamin D? Vitamin D preparations: types, names and indications for use. How to take vitamin D3 for infants

International name – Vitamin D, antirachitic vitamin, ergocalciferol, cholecalciferol, viosterolol, sun vitamin. Chemical name – ergocalciferol (vitamin D 2) or cholecalciferol (vitamin D 3), 1,25(OH)2D (1alpha,25-dihydroxyvitamin D)

Helps maintain healthy bones, keeping them strong and strong. Responsible for healthy gums, teeth, muscles. Essential for maintaining cardiovascular health, helps prevent dementia and improve brain function.

Vitamin D is a fat-soluble substance necessary for mineral balance in the body. There are several forms of vitamin D, the most studied and main forms important for humans are cholecalciferol(vitamin D 3, which is synthesized by the skin under the influence of ultraviolet rays) and ergocalciferol(vitamin D 2 contained in some foods). Combined with regular exercise, proper nutrition, calcium and magnesium, they are responsible for the formation and maintenance of healthy bones. Vitamin D is also responsible for the absorption of calcium in the body. In combination, they help prevent the occurrence and reduce the risk of bone fractures. This is a vitamin that has a positive effect on muscle health and also protects against diseases such as rickets and osteomalacia.

A Brief History of the Discovery of the Vitamin

Diseases associated with vitamin D deficiency were known to mankind long before its official discovery.

• Mid-17th century - scientists Whistler and Glisson first carried out an independent study of the symptoms of the disease, later called " rickets" However, scientific treatises did not say anything about measures to prevent the disease - sufficient sunlight or good nutrition.
• 1824 - Dr. Schötte first prescribed fish oil as a treatment for rickets.
• 1840 - Polish doctor Sniadecki issued a report that children living in regions with low solar activity (in the polluted center of Warsaw) have a greater risk of developing rickets compared to children living in villages. This statement was not taken seriously by his colleagues, since it was believed that the sun's rays could not affect the human skeleton.
• Late 19th century - More than 90% of children living in polluted European cities suffered from rickets.
• 1905-1906 - a discovery was made that when there is a lack of certain substances from food, people get sick with one or another disease. Frederick Hopkins suggested that to prevent diseases such as scurvy and rickets, it is necessary to consume certain special components from food.
• 1918 - the discovery was made that hounds consuming fish oil do not develop rickets.
• 1921 - the scientist Palm's assumption about a lack of sunlight as the cause of rickets was confirmed by Elmer McCollum and Margarita Davis. They demonstrated that by giving laboratory rats fish oil and exposing them to sunlight, the rats' bone growth accelerated.
• 1922 - McCollum isolated a “fat-soluble substance” that prevents rickets. Since vitamins A, B and C of a similar nature had been discovered shortly before, it seemed logical to name the new vitamin in alphabetical order – D.
• 1920s - Harry Steenbock patented a method of irradiating foods with UV rays to enrich them with vitamin D.
• 1920-1930 – Various forms of vitamin D were discovered in Germany.
• 1936 - It was proven that vitamin D is produced by the skin under the influence of sunlight, as well as the presence of vitamin D in fish oil and its effect on the treatment of rickets.
• Beginning in the 1930s, some foods in the United States began to be fortified with vitamin D. In the post-war period in Britain, there were frequent poisonings from an excess of vitamin D in dairy products. Since the early 1990s, numerous studies have appeared on the decline in vitamin levels in the world's population.

Foods with the highest vitamin D content

The approximate content of D2+D3 per 100 g of product is indicated

Daily requirement for vitamin D

In 2016, the European Committee on Food Safety established the following recommended daily intake of vitamin D, regardless of gender:

• children 6-11 months – 10 mcg (400 IU);
• children over one year old and adults – 15 mcg (600 IU).

It is worth noting that many European countries set their own vitamin D intake, depending on solar activity throughout the year. For example, in Germany, Austria and Switzerland, the norm since 2012 is the consumption of 20 mcg of vitamin per day, since in these countries the amount obtained from food is not enough to maintain the required level of vitamin D in the blood plasma - 50 nanomol/liter. In the US, recommendations are slightly different: people over the age of 71 are advised to consume 20 mcg (800 IU) per day.

Many experts believe that the minimum amount of vitamin D received should be increased to 20-25 mcg (800-1000 IU) per day for adults and older adults. In some countries, scientific committees and nutrition societies have managed to increase the level of daily intake to achieve optimal concentrations of the vitamin in the body.

When does the need for vitamin D increase?

Although our body is capable of producing vitamin D on its own, the need for it may increase in several cases. Firstly, dark skin color reduces the body's ability to absorb ultraviolet B radiation needed to produce the vitamin. In addition, the use sunscreen with an SPF factor of 30 reduces the ability to synthesize vitamin D by 95 percent. In order to stimulate the production of the vitamin, the skin must be fully exposed to the sun's rays.

People living in northern parts of the Earth, in polluted regions, working at night and spending daytime indoors, or those who work from home should ensure that they get adequate levels of the vitamin from food. Infants who are exclusively breastfed should receive a vitamin D supplement, especially if the infant has dark skin or minimal sun exposure. For example, American doctors advise giving infants 400 IU of vitamin D per day in the form of drops.

Physicochemical properties of vitamin D

Vitamin D is a group fat-soluble substances, which promote the absorption of calcium, magnesium and phosphates in the body through the intestines. There are five forms of vitamin D 1 (a mixture of ergocalciferol and lumisterol), D 2 (ergocalciferol), D 3 (cholecalciferol), D 4 (dihydroergocalciferol) and D 5 (sitocalciferol). The most common forms are D 2 and D 3 . They are what we are talking about when they say “vitamin D” without indicating a specific number. These are secosteroids in nature. Vitamin D3 is produced photochemically, under the influence of ultraviolet rays, from the protosterol 7-dehydrocholesterol, which is present in the epidermis of the skin of humans and most higher animals. Vitamin D2 is present in some foods, especially portobello and shiitake mushrooms. These vitamins are relatively stable at high temperatures, but are easily destroyed by oxidizing agents and mineral acids.

Beneficial properties and its effect on the body

According to the European Committee for Food Safety, vitamin D has been confirmed to have clear health benefits. Among the positive effects of its use are:

• normal development of bones and teeth in infants and children;
• maintaining the condition of teeth and bones;
• normal immune system function and healthy immune system response;
• reducing the risk of falls, which often cause fractures, especially in people over 60 years of age;
• normal absorption and action of calcium and phosphorus in the body, maintaining normal calcium levels in the blood;
• normal cell division.

In fact, vitamin D is a prohormone and has no biological activity on its own. Only after it undergoes metabolic processes (first turning into 25(OH) D 3 in the liver, and then into 1a,25(OH) 2 D 3 and 24R,25(OH) 2 D 3 in the kidneys) are produced biologically active molecules. In total, approximately 37 vitamin D3 metabolites have been isolated and chemically characterized.

The active metabolite of vitamin D (calcitriol) performs its biological functions by binding to vitamin D receptors, which are mainly located in the nuclei of certain cells. This interaction allows vitamin D receptors to act as a factor that modulates the expression of genes for transporting proteins (such as TRPV6 and calbindin) that are involved in calcium absorption in the intestine. The vitamin D receptor is a member of the superfamily of nuclear receptors for steroid and thyroid hormones and is found in the cells of most organs - the brain, heart, skin, gonads, prostate and mammary glands. Activation of the vitamin D receptor in the cells of the intestines, bones, kidneys and parathyroid glands leads to the maintenance of calcium and phosphorus levels in the blood (with the help of parathyroid hormone and calcitonin), as well as the maintenance of the normal composition of skeletal tissues.

Key elements of the vitamin D endocrine pathway are:

1. 1 photoconversion of 7-dehydrocholesterol to vitamin D 3 or dietary intake of vitamin D 2 ;
2. 2 metabolism of vitamin D 3 in the liver to 25(OH)D 3 - the main form of vitamin D circulating in the blood;
3. 3 the functioning of the kidneys as endocrine glands for the metabolism of 25(OH)D3 and its conversion into two main dihydroxylated metabolites of vitamin D - 1a,25(OH)2D3 and 24R,25(OH)2D3;
4. 4 systemic transfer of these metabolites to peripheral organs via plasma vitamin D binding protein;
5. 5 reaction of the above-mentioned metabolites with receptors located in the nuclei of cells of the corresponding organs, with subsequent biological responses (genomic and immediate).

Interaction with other elements

Our body is a very complex biochemical mechanism. The way vitamins and minerals interact with each other is interconnected and depends on many factors. The effect that vitamin D produces in our body is directly dependent on the amount of other vitamins and minerals called cofactors. There are a number of such cofactors, but the most important of them are:

• Calcium: One of the most important functions of vitamin D is to stabilize calcium levels in the body. This is why maximum calcium absorption occurs only when there is sufficient vitamin D in the body.
• magnesium: every organ in our body needs magnesium in order to properly perform its functions, as well as fully transform food into energy. Magnesium helps the body absorb vitamins and minerals such as calcium, phosphorus, sodium, potassium and vitamin D. Magnesium can be obtained from foods such as spinach, nuts, seeds, and whole grains.
• Vitamin K: Our bodies need it to heal wounds (by allowing blood to clot) and to maintain healthy bones. Vitamin D and K work together to strengthen bones and ensure their proper development. Vitamin K is present in foods such as kale, spinach, liver, eggs and hard cheese.
• zinc: it helps us fight infections, form new cells, grow and develop, and fully absorb fats, carbohydrates and proteins. Zinc helps vitamin D to be absorbed in skeletal tissues and also helps transport calcium into bone tissue. Large amounts of zinc are found in meat, as well as some vegetables and grains.
• boron: our body needs little of it, but, nevertheless, it plays an important role in the metabolism of many substances, including vitamin D. Boron is found in foods such as peanut butter, wine, avocados, raisins and some leafy vegetables .
• Vitamin A: Along with vitamin D, retinol and beta-carotene help our “genetic code” work. If the body does not have enough vitamin A, vitamin D will not be able to function properly. Vitamin A can be obtained from carrots, mangoes, liver, butter, cheese and milk. It must be remembered that vitamin A is fat-soluble, so if it comes from vegetables, it must be combined with various fat-containing foods. This way we can get the most out of our food.

Healthy food combinations with vitamin D

The combination of vitamin D and calcium is considered the most beneficial. Our body needs this vitamin in order to fully absorb calcium, which is essential for our bones. Good combinations of products in this case would be, for example:

• grilled salmon and lightly braised kale;
• omelet with broccoli and cheese;
• tuna and cheese sandwich on whole grain bread.

It is useful to combine vitamin D with magnesium, for example, by eating sardines with spinach. This combination may even reduce the risk of heart disease and colon cancer.

Of course, it is better to get the required amount of vitamin directly from food and spending as much time as possible in the fresh air, allowing the skin to produce vitamin D. Taking vitamins in tablets is not always useful, and only a doctor can determine how much of a particular element our body needs. Taking vitamins incorrectly can often harm us and lead to certain diseases.

Application in official medicine

Vitamin D is essential for regulating the absorption and levels of the minerals calcium and phosphorus in the body. It also plays an important role in maintaining proper bone structure. Walking on a sunny day is an easy and reliable way to get the right dose of vitamins for most of us. When exposed to sunlight on the face, arms, shoulders and legs once or twice a week, the skin will produce a sufficient amount of the vitamin. The exposure time depends on age, skin type, time of year, day. It's amazing how quickly vitamin D stores can be restored with sunlight. Just 6 days of intermittent sun exposure can compensate for 49 days without sun. Our body's fat reserves serve as a storehouse for the vitamin, which is gradually released in the absence of ultraviolet rays.

However, vitamin D deficiency is more common than you might expect. People living in northern latitudes are especially at risk. But it can occur even in sunny climates, since residents of southern countries spend a lot of time indoors and use sunscreen to avoid excessive solar activity. In addition, deficiency often occurs in older people.

Vitamin D as a medicine is prescribed in the following cases:

1. 1 with low phosphorus levels in the blood due to a hereditary disease (familial hypophosphatemia). Taking vitamin D along with phosphate supplements is effective in treating bone disorders in people with low blood phosphate levels;
2. 2 with low phosphate content in Fanconi syndrome;
3. 3 with low calcium levels in the blood due to low levels of parathyroid hormones. In this case, vitamin D is taken orally;
4. 4, taking vitamin D (cholecalciferol) is effective in the treatment of osteomalacia (softening of bones), including that caused by liver disease. In addition, ergocalciferol may help with osteomalacia due to certain medications or poor intestinal digestibility;
5. 5 for psoriasis. In some cases, topical vitamin D along with medications containing corticosteroids is a very effective treatment for psoriasis;
6. 6 for renal osteodystrophy. Taking vitamin D prevents bone loss in people with kidney failure;
7. 7 rickets. Vitamin D is used in the prevention and treatment of rickets. People with kidney failure need to take a special form of the vitamin, calcitriol;
8. 8 when taking corticosteroids. There is evidence that vitamin D in combination with calcium improves bone density in people taking corticosteroids;
9. 9 osteoporosis. Vitamin D 3 is thought to prevent bone loss and weakening of bones in osteoporosis.

Some studies show that getting enough vitamin D can reduce your risk of developing some types of cancer. For example, it was observed that in men taking high doses of the vitamin, the risk of colon cancer was reduced by 29% compared with men who had low levels of 25(OH)D in the blood (study of more than 120 thousand men over five years). Another study tentatively concluded that women who had adequate sun exposure and took vitamin D supplements had a lower risk of breast cancer after 20 years.

There is evidence that vitamin D may reduce the risk of autoimmune diseases, in which the body produces an immune response against its own tissues. Vitamin D 3 has been found to modulate autoimmune reactions mediated by immune cells (“T cells”) such that autoimmune reactions are reduced. We are talking about diseases such as type 1 diabetes, multiple sclerosis and rheumatoid arthritis.

Epidemiological and clinical studies suggest an association between higher blood levels of 25(OH)D and lower blood pressure, suggesting that 25(OH)D reduces the synthesis of the enzyme renin, playing a key role in blood pressure regulation.

Low levels of vitamin D may increase your chance of getting tuberculosis. Preliminary evidence suggests that vitamin D may be a useful addition to conventional treatment for this infection.

Vitamin D dosage forms

Vitamin D in dosage form can be found in different forms - in the form of drops, alcohol and oil solutions, injection solutions, capsules, both alone and in combination with other beneficial substances. For example, there are such multivitamins as:

• cholecalciferol and calcium carbonate (the most popular combination of calcium and vitamin D);
• alfacalcidol and calcium carbonate (active form of vitamin D3 and calcium);
• calcium carbonate, calciferol, magnesium oxide, zinc oxide, copper oxide, manganese sulfate and sodium borate;
• calcium carbonate, cholecalciferol, magnesium hydroxide, zinc sulfate heptahydrate;
• calcium, vitamin C, cholecalciferol;
• and other additives.

In supplements and fortified foods, vitamin D is available in two forms: D 2 ( ergocalciferol) and D 3 ( cholecalciferol). Chemically, they differ only in the structure of the side chain of the molecule. Vitamin D2 is produced by ultraviolet irradiation of ergosterol from yeast, and vitamin D3 by irradiation of 7-dehydrocholesterol from lanolin and chemical conversion of cholesterol. The two forms are traditionally considered equivalent based on their ability to treat rickets, and, indeed, most of the steps involved in the metabolism and action of vitamin D2 and vitamin D3 are identical. Both forms are effective in increasing 25(OH)D levels. No specific conclusions have been drawn about any different effects of these two forms of vitamin D. The only difference appears when high doses of the vitamin are used, in which case vitamin D 3 is more active.

The following dosages of vitamin D have been studied in scientific studies:

• to prevent osteoporosis and fractures - 400-1000 International Units per day;
• to prevent falls - 800-1000 IU of vitamin D in combination with 1000-2000 mg of calcium per day;
• to prevent multiple sclerosis - long-term intake of at least 400 IU per day, preferably in the form of a multivitamin;
• to prevent all types of cancer - 1400-1500 mg of calcium per day, in combination with 1100 IU of vitamin D 3 (especially for women during menopause);
• for muscle pain from taking drugs called statins: vitamin D 2 or D 3, 400 IU per day.

Most supplements contain 400 IU (10 mcg) of vitamin D.

Use of vitamin D in folk medicine

Traditional medicine has long valued foods rich in vitamin D. There are many recipes with them used to treat certain diseases. The most effective of them:

• eating fish oil(both in capsule form and in natural form - eating 300 g/week of fatty fish): for the prevention of hypertension, arrhythmia, breast cancer, for maintaining a healthy body weight, against psoriasis and to protect the lungs when smoking, for arthritis , depression and stress, inflammatory processes. Ointment recipe for skin itching, psoriasis, urticaria, herpetic dermatitis: 1 teaspoon of elecampane, 2 teaspoons of fish oil, 2 teaspoons of rendered lard.
• use of chicken eggs: raw egg yolk is useful for fatigue and overwork (for example, use a mixture of gelatin powder and raw egg dissolved in 100 m of water; a drink made from warm milk, raw chicken yolk and sugar). When coughing, use a mixture of 2 raw yolks, 2 teaspoons of butter, 1 dessert spoon of flour and 2 dessert spoons of honey. In addition, there are several recipes for the treatment of various diseases of the gastrointestinal tract. For example, in case of unpleasant sensations in the liver, folk recipes advise drinking 2 beaten egg yolks, drinking 100 ml of mineral water and applying a warm heating pad to the right side for 2 hours. There are also recipes using eggshells. For example, for chronic catarrh of the stomach and intestines, high acidity, constipation or worms, folk recipes advise taking half a teaspoon of ground eggshells in the morning on an empty stomach. And to reduce the risk of stone formation, you can use calcium salt of citric acid (egg shell powder is poured with lemon juice, wine or apple cider vinegar, stirred until dissolved, or 2-3 drops of lemon juice are dripped onto 1 tablespoon of egg powder). An infusion of egg shells and citric acid is also considered an effective remedy for arthritis. For radiculitis, it is recommended to rub your back with a mixture of raw egg and vinegar. Raw eggs are considered a good remedy for psoriasis; raw yolks (50 grams) are mixed with birch tar (100 grams) and thick cream. For burns, use an ointment made from black-fried yolks of hard-boiled eggs.
• milk, rich in vitamin D, is a whole storehouse of folk recipes for various diseases. For example, goat milk helps with fever, inflammation, belching, shortness of breath, skin diseases, cough, tuberculosis, sciatic nerve disease, urinary system, allergies and insomnia. For severe headaches, it is recommended to drink 200 grams of goat's milk with ground viburnum berries and sugar. To treat pyelonephritis, folk recipes advise drinking milk with apple peel. For exhaustion and asthenia, you can use oatmeal infusion with milk (simmer 1 glass of oatmeal in the oven with 4 glasses of milk for 3-4 hours on low heat). For kidney inflammation, you can use an infusion of birch leaves with milk. It is also recommended to take a decoction of horsetail in milk for inflammation of the urinary system and swelling. Milk with mint will help relieve an attack of bronchial asthma. For persistent migraines, use a mixture of boiling milk with a fresh egg mixed in it for several days to one week. To reduce acidity, pumpkin porridge cooked in milk is useful. For weeping eczema, lubricate the affected areas with a decoction of 600 ml of milk with 100 grams of black radish seeds and 100 grams of hemp seeds (you can also apply compresses for 2 hours). For dry eczema, use an application of a decoction of 50 grams of fresh burdock leaves in 500 ml of milk.
• butter used, for example, for bedsores and trophic ulcers - in the form of an ointment made from 1 part marsh cudweed powder, 4 parts oil and 4 parts honey.

Vitamin D in the latest scientific research

Taking a high dose of vitamin D for four months has been found to slow the hardening of blood vessels in overweight, dark-skinned young adults. Hard blood vessels are a precursor to many fatal heart diseases, and vitamin D deficiency appears to be a major contributing factor. According to research from the Medical Institute of Georgia, USA, it was observed that very high doses of the vitamin (4000 International Units per day, instead of the recommended 400-600 IU) reduced the hardening of blood vessels by a record 10.4 percent over 4 months.

2000 IU reduced it by 2%, 600 IU led to a deterioration of 0.1%. At the same time, in the group taking placebo, vascular condition worsened by 2.3%. Overweight people, especially black people, are at risk of not getting enough vitamin D in their bodies. Dark skin absorbs less sunlight, and fat interferes with the production of the vitamin.

Vitamin D supplements may help relieve painful irritable bowel syndrome, according to the latest research from scientists at the University of Sheffield's Department of Oncology and Metabolism.

The study found that vitamin D deficiency is common in patients with IBS, regardless of their ethnicity. In addition, the effect of this vitamin on the symptoms of the disease was studied. While scientists say further research is needed, the results so far suggest that taking the vitamin in dosage form reduces IBS symptoms such as abdominal pain, bloating, diarrhea and constipation. “From the findings, it is clear that all people suffering from irritable bowel syndrome should have their vitamin D levels checked. This is a poorly understood disease that directly affects the quality of life of patients. At this time, we still don’t know what causes it and how to treat it,” says Dr. Bernard Corfi, leader of the study.

Clinical trial results published in the Journal of the American Osteopathic Association show that up to one billion of the world's population may be completely or partially deficient in vitamin D due to chronic illness and regular use of sunscreen.

“We're spending more and more time indoors, and when we go outside we tend to put on sunscreen, and ultimately stop our bodies from producing vitamin D,” says Kim Pfotenhauer, a doctoral student at Touro University and a researcher on the subject. “Although overexposure to the sun can lead to skin cancer, moderate amounts of ultraviolet rays are beneficial and necessary for increasing vitamin D levels.” It has also been noted that chronic diseases—type 2 diabetes, malabsorption, kidney disease, Crohn's disease, and celiac disease—markably inhibit the absorption of vitamin D from food sources.

Low levels of vitamin D in newborns were associated with an increased likelihood of developing autism spectrum disorder in children by age 3, according to a recent study published in the journal Bone and Mineral Research.

In a study of 27,940 Chinese infants, 310 were diagnosed with autism spectrum disorder at age 3 years, representing a prevalence of 1.11 percent. When comparing data on 310 children with ASD with 1,240 control subjects, the risk of ASD was significantly increased in each of the three lowest quartiles of vitamin D levels at birth compared with the highest quartile: increased risk of ASD 260 percent in the lowest quartile, 150 percent in second quartile and 90 percent in the third quartile. "Newborn vitamin D status was significantly associated with risk of autism and intellectual disability," said the study's senior author, Dr. Yuan-Ling Zheng.

Maintaining adequate levels of vitamin D helps prevent the onset of some inflammatory diseases such as rheumatoid arthritis, say scientists from the University of Birmingham.

However, while vitamin D is effective in preventing inflammation, it is not as effective once the inflammatory disease is diagnosed. Rheumatoid arthritis, along with other diseases, causes the body to become resistant to vitamin D. Another key finding of the study was that the effect of vitamin D on inflammation cannot be predicted by studying cells from healthy people or even blood cells from patients who suffer from inflammation. The scientists concluded that even if vitamin D is prescribed for inflammatory diseases, doses should be significantly higher than currently prescribed. Treatment should also correct the sensitivity of immune cells in the joint to vitamin D. In addition to the already known positive effect of vitamin D on skeletal tissue, it also acts as a powerful modulator of immunity - this vitamin can reduce the inflammatory process in autoimmune diseases. Vitamin D deficiency is common in patients with rheumatoid arthritis and may be prescribed as a medication by doctors.

Getting enough vitamin D in the body during infancy and childhood reduces the risk of developing an autoimmune reaction to the islets of Langerhans (clusters of endocrine cells, mainly in the tail of the pancreas) with an increased genetic risk of type 1 diabetes.

“For many years, there has been disagreement among researchers about whether vitamin D can reduce the risk of developing self-immunity and type 1 diabetes,” said Dr. Norris, who led the study. Type 1 diabetes is a chronic autoimmune disease whose incidence is increasing annually by 3-5 percent worldwide. The disease is currently the most common metabolic disorder in children under 10 years of age. The number of new cases is particularly high in young children. And the risks appear to be higher at higher latitudes, further north of the equator. Vitamin D is a protective factor in type 1 diabetes because it regulates the immune system and autoimmunity. Moreover, vitamin D status varies by latitude. But the associations between vitamin D levels and autoimmune response to islets of Langerhans have been inconsistent, due to different study designs as well as varying vitamin D levels in different populations. This study is unique in its kind and shows that higher levels of vitamin D in childhood significantly reduce the risk of this autoimmune reaction. "Because the current results do not provide causal evidence for this process, we are designing prospective studies to see whether vitamin D intervention can prevent type 1 diabetes," Dr. Norris said.

Taking vitamin D supplements may help protect against acute respiratory infections and influenza, according to research from Queen Mary University of London (QMUL).

The findings, which appeared in the British Medical Journal, were based on clinical trials among 11,000 participants in 25 clinical trials conducted in 14 countries, including the UK, the United States, Japan, India, Afghanistan, Belgium, Italy, Australia and Canada. It should be noted that individually these trials showed conflicting results - some participants reported that vitamin D helped protect the body from SARS, and some reported that it had no noticeable effect. “The fact is that the immune effect of vitamin D supplements is most pronounced in those patients who have low vitamin D levels to begin with, when taken every day or every week.” Vitamin D—often called the “sunshine vitamin”—protects the body from airborne infections by increasing levels of antimicrobial peptides—natural antibiotic substances—in the lungs. The finding may also explain why we get colds and flu most often in the winter and spring. During these seasons, the level of vitamin D in the body is the lowest. In addition, vitamin D protects against asthma attacks that cause respiratory infections. Taking the vitamin daily or weekly reduced the likelihood of developing ARVI in people with levels below 25 nanomol/liter. But even those who had enough vitamin D in their bodies benefited, although their effect was more modest (10 percent risk reduction). In general, the reduction in the risk of catching a cold after taking vitamin D was on par with the protective effect of the injectable flu vaccine.

The use of vitamin D in cosmetology

Vitamin D can be used in a variety of homemade mask recipes for skin and hair. It nourishes the skin and hair, gives them strength and elasticity, and rejuvenates. We offer you the following recipes:

• Skin masks with fish oil. These masks are suitable for aging skin, especially dry skin. Fish oil goes well with honey: for example, a mixture of 1 tablespoon of yeast, full-fat sour cream, 1 teaspoon of fish oil and honey is effective. This mask must first be placed in a water bath in hot water until the fermentation process begins, then stir and apply to the skin for 10 minutes. You can also use a mixture of fish oil and honey (1 teaspoon each, with the addition of 1 tablespoon of boiled water) - this mask after 10-12 minutes will help smooth out fine wrinkles and improve skin color. Another effective mask recipe with fish oil, which is suitable for any skin type, will give it freshness and beauty. For such a mask you need to mix 1 teaspoon of eggshell powder, 1 teaspoon of fish oil, 1 egg yolk, 2 teaspoons of mustard honey and half a glass of boiled pumpkin pulp. The mask is applied to the face warm and washed off with cool water after 10-15 minutes.
• Skin masks with egg. These masks are very popular and effective for all ages and skin types. For example, for aging skin, a moisturizing mask with 1 tablespoon of crushed dried lemon peel, 1 egg yolk and 1 teaspoon of olive oil is suitable. For any skin type, a nourishing and cleansing mask made from 2 proteins, 1 tablespoon of honey, half a teaspoon of almond oil and 2 tablespoons of oatmeal is suitable. For dry, aging skin, you can use a mask of 1 tablespoon of banana puree, 1 yolk, sour cream and honey. To get rid of wrinkles, a mask of 1 yolk, 1 teaspoon of vegetable oil and 1 teaspoon of aloe leaf juice (previously kept in the refrigerator for 2 weeks) is suitable. To care for oily skin and tighten pores, a mask containing 2 tablespoons of cottage cheese, half a teaspoon of liquid honey and one egg is suitable. A whitening mask for any skin type contains half a glass of carrot juice, 1 teaspoon of potato starch and half a raw egg yolk, applied for 30 minutes and washed off in a contrasting way - either cold or hot water.
• Hair and scalp masks with vitamin D. Such masks most often include an egg or egg yolk. For example, for hair growth, use a mask that contains 1 tablespoon of lemon juice, 1 tablespoon of onion juice and 1 egg yolk - applied once a week for 2 hours before washing your hair. For dry hair, a mask with 2 egg yolks, 2 tablespoons of burdock oil and 1 teaspoon of calendula tincture is suitable. Nourishing mask for thinning hair – 1 tablespoon of burdock oil, 1 egg yolk, 1 teaspoon of honey, 2 teaspoons of onion juice and 2 teaspoons of liquid soap (apply this mask an hour or two before washing your hair). To strengthen hair roots and get rid of dandruff, use a mask made from an infusion of 1 tablespoon of crushed plantain leaves, burdock, 2 tablespoons of aloe juice and egg yolk. Effective masks against hair loss are a mask with cinnamon (1 egg, 2 tablespoons of burdock oil, 1 teaspoon of ground cinnamon and 1 teaspoon of honey; rinse after 15 minutes) and a mask with sunflower oil (1 tablespoon of sunflower oil and 1 yolk, washes off after 40 minutes). Also useful for strengthening and shining hair is a mask with 1 tablespoon of honey, 1 tablespoon of castor oil, 1 yolk and 1 tablespoon of cognac. To restore dry and damaged hair, use a mask with 2 yolks, 1 tablespoon of hazelnut oil and a drop of lemon essential oil.

Use of vitamin D in livestock

Unlike humans, cats, dogs, rats and poultry must obtain vitamin D from food, since their skin is not able to produce it on its own. Its main function in the animal’s body is to maintain normal bone mineralization and skeletal growth, regulate the parathyroid gland, immunity, metabolism of various nutrients and protect against cancer. Through research, it has been proven that dogs cannot be cured of rickets by exposing them to ultraviolet radiation. For normal development, growth, and reproduction, the food of cats and dogs must also contain a sufficiently high amount of calcium and phosphorus, which help the body synthesize vitamin D.

However, because natural foods contain low amounts of this vitamin, most commercially prepared pet foods are synthetically fortified with it. Therefore, vitamin D deficiency in pets is extremely rare. Pigs and ruminants do not need to obtain the vitamin from food, provided they are exposed to sunlight for a sufficient amount of time. Birds also exposed to UV rays for long periods of time can produce some vitamin D, but to maintain skeletal health and the strength of the shells of the eggs they lay, the vitamin must also be obtained from their diet. As for other animals, namely carnivores, it is believed that they can get enough vitamin D by eating fat, blood and liver.

Use in crop production

Although adding fertilizers to soil can improve plant growth, dietary supplements intended for human consumption, such as calcium or vitamin D, are not thought to provide clear benefit to plants. The main plant nutrients are nitrogen, phosphorus and potassium. Other minerals, such as calcium, are needed in small quantities, but plants use a different form of calcium from supplements. According to popular belief, plants do not absorb vitamin D from soil or water. At the same time, there are some practical independent studies that prove that adding vitamin D to the water with which plants are watered speeds up their growth (as the vitamin helps the roots absorb calcium).

• To draw attention to such an important problem as a lack of vitamin D, in 2016, the insurance company Daman created an unusual cover for the magazine. The text on it was applied with a special photosensitive paint. And in order to see it, people had to go outside, look for sunlight, thereby receiving a certain portion of this vitamin.
• The sun's rays, which help synthesize vitamin D in the skin, cannot penetrate glass - for this reason, we are unlikely to be able to take a sunbath while sitting in a car, indoors or in a solarium.
• Sunscreen, even with SPF 8, can block up to 95% of vitamin D production. Vitamin D deficiency can occur, so spending a little time outdoors without wearing sunscreen is very beneficial for your overall health.
• A clinical study from the University of Minnesota found that people who started a diet higher in vitamin D were able to lose weight faster and easier than people with vitamin D deficiency, even though both groups followed the same standard low-calorie diet.
• Vitamin D is unique in that it is not used in the body like most vitamins. In fact, it is more likely to be classified as a hormone. Vitamin D is so important that it actually regulates the activity of more than 200 genes - many times more than any other vitamin.

Contraindications and precautions

Signs of Vitamin D Deficiency

The vitamin D molecule is quite stable. A small percentage of it is destroyed during cooking, and the longer the product is exposed to heat, the more vitamin we lose. So, when boiling eggs, for example, 15% is lost, when frying - 20%, and when baking for 40 minutes we lose 60% of vitamin D.

The primary function of vitamin D is to maintain calcium homeostasis, which is essential for the development, growth and maintenance of a healthy skeleton. With a deficiency of vitamin D, it is impossible to obtain complete absorption of calcium and meet the body's needs. Vitamin D is required for effective dietary absorption of calcium from the intestines. Symptoms of vitamin D deficiency are sometimes difficult to identify and may include general fatigue and aches and pains. Some people have no symptoms at all. However, there are a number of common indications that may indicate a lack of vitamin D in the body:

• frequent infectious diseases;
• back and bone pain;
• depression;
• long wound healing;
• hair loss;
• muscle pain.

If vitamin D deficiency continues for long periods of time, it can lead to:

• diabetes;
• hypertension;
• fibromyalgia;
• chronic fatigue syndrome;
• osteoporosis;
• neurodegenerative diseases such as Alzheimer's disease.

A lack of vitamin D may contribute to the development of certain types of cancer, especially breast, prostate and colon cancer.

Signs of excess vitamin D

Although most people take vitamin D supplements without any complications, overdose does occur. These are called vitamin D toxicity. Vitamin D toxicity, where it can cause harm, usually occurs if you take 40,000 International Units per day for several months or longer, or take a very large single dose.

An overabundance of 25(OH)D may develop if you:

• took more than 10,000 IU per day daily for 3 months or longer. However, vitamin D toxicity is more likely to develop if you take 40,000 IU per day every day for 3 months or more;
• took more than 300,000 IU within the last 24 hours.

Vitamin D is fat soluble, meaning it is difficult for the body to get rid of it if too much is taken. When this occurs, the liver produces too much of a chemical called 25(OH)D. When levels are too high, high blood calcium levels (hypercalcemia) can occur.

Symptoms of hypercalcemia include:

• bad feeling;
• poor appetite or loss of appetite;
• feeling of thirst;
• frequent urination;
• constipation or diarrhea;
• abdominal pain;
• muscle weakness or muscle pain;
• bone pain;
• confusion;
• feeling tired.

In some rare diseases, hypercalcemia can occur even when vitamin D levels are low. These diseases include primary hyperparathyroidism, sarcoidosis, and a number of other rare diseases.

Vitamin D should be taken with caution in diseases such as granulomatous inflammation - in these diseases the body does not control the amount of vitamin D it uses and what level of calcium in the blood it needs to maintain. Such diseases are sarcoidosis, tuberculosis, leprosy, coccidioidomycosis, histoplasmosis, cat scratch disease, paracoccidioidomycosis, granuloma annulare. For these diseases, vitamin D is prescribed only by a doctor and taken strictly under medical supervision. Vitamin D should be taken with great caution if you have lymphoma.

Interaction with other drugs

Vitamin D supplements may interact with several types of medications. A few examples are given below. Individuals taking these medications on a regular basis should discuss taking vitamin D with their health care providers.

Corticosteroid drugs such as prednisone, prescribed to reduce inflammation, can reduce calcium absorption and interfere with the metabolism of vitamin D. These effects may further contribute to bone loss and the development of osteoporosis. Some weight-loss and cholesterol-lowering drugs may reduce the absorption of vitamin D. Drugs that control epileptic seizures increase liver metabolism and reduce calcium absorption.

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Good day, dear visitors of the project “Good IS!” ", section " "!

I am pleased to present to your attention information about vitamin D.

The main functions of vitamin D in the human body are: ensuring the absorption of calcium from food in the small intestine (mainly in the duodenum), stimulating the synthesis of a number of hormones, and also participating in the regulation of cell reproduction and metabolic processes.

General information

Vitamin D, aka calciferol(lat. Vitamin D, Calciferol) - a group of biologically active substances that regulate metabolism with.

Also called vitamin D "sunshine vitamin".

Forms of Vitamin D:

Vitamin D1- combination of ergocalciferol with lumisterol, 1:1.

Vitamin D2 (ergocalciferol) ( Ergocalciferol) - isolated from yeast. Its provitamin is ergosterol;
(3β,5Z,7E,22E)-9,10-secoergosta-5,7,10 (19),22-tetraen-3-ol.
Chemical formula: C28H44O.
CAS: 50-14-6.
Vitamin D2 is very toxic, a dose of 25 mg is already dangerous (20 ml in oil). It is poorly excreted from the body, which leads to a cumulative effect.
Main symptoms of poisoning: nausea, malnutrition, lethargy, increased body temperature, muscle hypotension, drowsiness, followed by severe anxiety, convulsions.
Since 2012, Ergocalciferol has been excluded from the list of vital and essential drugs.

Vitamin D3 (cholecalciferol, Cholecalciferol)- isolated from animal tissues. Its provitamin is 7-dehydrocholesterol;
Systematic name:(3beta,5Z,7E)-9,10-Secocholesta-5,7,10(19)-trien-3-ol.
Chemical formula: C27H44O.
CAS: 67-97-0.
Restrictions on use: Organic heart damage, acute and chronic liver and kidney diseases, gastrointestinal diseases, gastric and duodenal ulcers, pregnancy, old age.
Contraindications: Hypersensitivity, hypercalcemia, hypercalciuria, calcium nephrourolithiasis, prolonged immobilization (large doses), active forms of pulmonary tuberculosis.

Vitamin D4 (22, 23-dihydro-ergocalciferol).
Systematic name:(3β,5E,7E,10α,22E)-9,10-secoergosta-5,7,22-trien-3-ol.
Chemical formula: C28H46O.
CAS: 67-96-9.

Vitamin D5 (24-ethylcholecalciferol, sitocalciferol). Isolated from wheat oils.

Vitamin D6 (22-dihydroethylcalciferol, stigma-calciferol).

Vitamin D usually means two vitamins - D2 and D3 - ergocalciferol and cholecalciferol, but more of them are D3 (cholecalciferol), so often on the Internet and other sources, vitamin D is labeled as cholecalciferol.

Vitamin D (cholecalciferol and ergocalciferol) are colorless and odorless crystals that are resistant to high temperatures. These vitamins are fat soluble, i.e. soluble in fats and organic compounds and insoluble in water.

Vitamin D units

The amount of vitamin D, like , is usually measured in international units (IU).

The activity of vitamin D preparations is expressed in international units (IU): 1 IU contains 0.000025 mg (0.025 mg) of chemically pure vitamin D. 1 μg = 40 IU

1 IU = 0.025 mcg cholecalciferol;
40 IU = 1 mcg cholecalciferol.

Vitamin D in history

The first mention of a disease caused by vitamin D deficiency, rickets, was found in the works of Soranus of Ephesus (98–138 AD) and the ancient physician Galen (131–211 AD).

Rickets was first briefly described only in 1645 by Whistler (England), and in detail by the English orthopedist Gleason in 1650.

In 1918, Edward Melanby proved in an experiment on dogs that cod oil acts as an antirachitic agent due to the content of a special vitamin. For some time it was believed that the antirachitic activity of cod oil depended on , already known at that time.

Later in 1921, McCollum, by passing a stream of oxygen through cod oil and inactivating vitamin A, discovered that the antirachitic effect of the oil persisted after that. Upon further search, another vitamin was found in the unsaponifiable part of cod oil, which has a strong anti-rachitic effect - vitamin D. Thus, it was finally established that food substances have the property of preventing and curing rickets mainly depending on the greater or lesser content of the vitamin in them D.

In 1919, Guldchinsky discovered the effective action of a mercury-quartz lamp (artificial “mountain sun”) in the treatment of children with rickets. From this period, insufficient exposure of children to ultraviolet sunlight began to be considered the main etiological factor of rickets.

And only in 1924 A. Hess and M. Weinstock obtained the first vitamin D1-ergosterol from vegetable oils after exposure to ultraviolet rays with a wavelength of 280–310 nm.

In 1928, Adolf Windaus received the Nobel Prize in Chemistry for the discovery of 7-dehydrocholesterol, a precursor to vitamin D.

Later, in 1937, A. Windaus isolated 7-dehydrocholesterol from the surface layers of pig skin, which was converted into active vitamin D3 under ultraviolet radiation.

The main function of vitamin D is to ensure normal growth and development of bones, prevent rickets and. It regulates mineral metabolism and promotes calcium deposition in bone tissue and dentin, thus preventing osteomalacia (softening) of bones.

Upon entering the body, vitamin D is absorbed in the proximal small intestine, and always in the presence of bile. Part of it is absorbed in the middle sections of the small intestine, a small part - in the ileum. After absorption, calciferol is found in the composition of chylomicrons in free form and only partially in the form of ester. Bioavailability is 60-90%.

Vitamin D affects general metabolism in the metabolism of Ca2+ and phosphate (HPO2-4). First of all, it stimulates the absorption of calcium, phosphates and calcium from the intestine. An important effect of the vitamin in this process is to increase the permeability of the intestinal epithelium to Ca2+ and P.

Vitamin D is unique - it is the only vitamin that acts as both a vitamin and a hormone. As a vitamin, it maintains the levels of inorganic P and Ca in the blood plasma above the threshold value and increases the absorption of Ca in the small intestine.

The active metabolite of vitamin D, 1,25-dioxycholecaciferol, which is formed in the kidneys, acts as a hormone. It affects the cells of the intestines, kidneys and muscles: in the intestines it stimulates the production of a carrier protein necessary for the transport of calcium, and in the kidneys and muscles it enhances the reabsorption of Ca++.

Vitamin D3 affects the nuclei of target cells and stimulates the transcription of DNA and RNA, which is accompanied by increased synthesis of specific proteins.

However, the role of vitamin D is not limited to protecting bones; it affects the body's susceptibility to skin diseases, heart disease and cancer. In geographic areas where food is poor in vitamin D, the incidence of vitamin D is increased, especially in youth.

It prevents muscle weakness, improves immunity (the level of vitamin D in the blood is one of the criteria for assessing the life expectancy of AIDS patients), and is necessary for the functioning of the thyroid gland and normal blood clotting.

Thus, with external use of vitamin D3, the characteristic scaly skin is reduced.

There is evidence that, by improving the absorption of calcium and magnesium, vitamin D helps the body restore the protective membranes surrounding the nerves, so it is included in the complex therapy of multiple sclerosis.

Vitamin D3 is involved in the regulation of blood pressure (particularly during pregnancy) and heartbeat.

Vitamin D inhibits the growth of cancer cells, making it effective in the prevention and treatment of breast, ovarian, prostate, brain cancer, and leukemia.

Daily requirement of vitamin D

What factors reduce the level of vitamin D in our body?

The need for vitamin D is higher in people lacking ultraviolet radiation:

- living in high latitudes,
- residents of regions with high air pollution,
- working night shifts or simply leading a nocturnal lifestyle,
- bedridden patients who do not spend time outdoors.

In people with dark skin (Negroid race, tanned people), the synthesis of vitamin D in the skin is reduced. The same can be said for older people (their ability to convert provitamins into vitamin D is halved) and those who follow a vegetarian diet or eat insufficient amounts of fat.

Intestinal and liver disorders and gall bladder dysfunction negatively affect the absorption of vitamin D.

In pregnant and lactating women, the need for vitamin D increases, because Additional amounts are needed to prevent rickets in children.

Vitamin D2 (ergocalciferol) is prescribed to pregnant women to prevent rickets in children at 30-32 weeks of pregnancy in divided doses over 10 days, for a total course of 400,000-600,000 IU. Nursing mothers - 500 IU daily from the first days of feeding until the child starts using the drug.

In order to prevent rickets, children begin to be given ergocalciferol from three weeks of age, the total dose per course is 300,000 IU.

For the treatment of rickets, 2000-5000 IU is prescribed daily for 30-45 days.

When treating with large doses of vitamin D preparations, it is recommended to simultaneously prescribe, and.

For prevention purposes, vitamin D3 (cholecalciferol) is usually prescribed, usually at a dose of 300-500 IU per day.

Beware, vitamin D!

Vitamin D is fat-soluble and therefore stored in the body, so if you overdose on it, serious problems can occur.

Because vitamin D increases calcium levels in the blood, excess vitamin D intake can lead to excess calcium levels. In this case, calcium can penetrate the walls of blood vessels and provoke the formation of atherosclerotic plaques. This process can be accelerated by a deficiency of magnesium in the body.

Vitamin D preparations are contraindicated for diseases such as:

Video about vitamin D

That's probably all. Health, peace and goodness to you!

Vitamin D (Calciferol) belongs to the class of fat-soluble vitamins. Due to its ability to be activated under the influence of sunlight, it is called solar. The main effect is aimed at calcium metabolism and strengthening bones. In addition, it has other positive physiological effects.

Discovery of Vit. D is associated with rickets in children. This disease of the musculoskeletal system (and not only) has been known since ancient times, and was studied in detail in the middle of the 17th century. Even then, the effectiveness of treating this disease with fish liver oil, or, simply, fish oil, was established.

In 1914, the English biochemist Elmer McCollum discovered and discovered it in fish oil. British veterinarian E. Mellenby, during experiments on dogs, confirmed the positive effect of fish oil - after its use, the symptoms of rickets in dogs regressed. Since fish oil contains vit. And, therefore, it is he who has an antirachitic effect.

But this was just a hypothesis. To confirm or refute it, in 1922 McCollum treated fish oil with a substance that destroys vit. A. After this, dogs with rickets continued to add fish oil to their food, but without it. The product was not expected to be beneficial this time. But, contrary to expectations, fish oil did not lose its healing properties during rickets.

Consequently, the issue is not in him at all, but in a completely different connection. Since the newly discovered vitamin was the fourth, it was named the letter D, the fourth in the alphabet. But soon scientists were surprised to find out that it itself does not have an antirachitic effect. Similar to Vit. And it is a precursor, a provitamin, which is transformed into a more active form, Calcitriol.

For the activity of vit. D is influenced by a whole range of factors. These are dietary fats, calcium, phosphorus, and sunlight. In 1924, it was found that irradiation with mercury-quartz lamps has a beneficial effect on children with rickets, and its amount in food irradiated with ultraviolet radiation increases.

In 1930-32, scientists Window and Askew obtained vitamin D in its crude form. A little later, Vit. was obtained by irradiation of ergosterol, provitamin D. D 2, Ergocalciferol, and in 1936 Vit. was isolated from tuna liver. D 3, Cholecalciferol. Immediately, in 1936, it was possible to obtain Cholecalciferol synthetically. And in 1937, scientists studied the structure of Ergocalciferol and Cholecalciferol. Subsequently, a technology for producing synthetic vitamin D from yeast on an industrial scale was developed.

Properties

Thus, D is not any specific substance, but a group of substances with a similar chemical structure that have the properties of vitamins. Such substances are called vitamers. And vitamers Vit. D is calciferols. The calciferol family includes six vitamers:

All varieties of calciferols have the same effect in humans and mammals. However, the activity of the last three forms, D 4 , D 5 and D 6 is quite low. At the same time, for D 2 and D 3 it is maximum. Therefore, under vit. D or Calciferol is usually used to designate these particular vitamers.

Each of the substances, Ergocalciferol and Cholecalciferol, is an odorless, white crystalline powder. Both vitamers are insoluble in water, but dissolve well in oils, alcohol, ether, and chloroform. They decompose under the influence of light, atmospheric oxygen, and various oxidizing substances.

Vit. D 2 (Ergocalciferol) with the chemical formula C 28 H 44 O has the nomenclature name (3 beta 5Z,7E,22E)-9,10-Secoergosta-5,7,10(19),22-tetraen-3-ol. Formula of vitamin 3 (Cholecalciferol): C 27 H 44 O. Name: (3beta,5Z,7E)-9,10-Secocholesta-5,7,10 (19)-trien-3-ol.

Physiological action

Each vitamin is unique in its own way, and vit. D is no exception. Its uniqueness lies in the fact that among all, it is both a vitamin and a hormone. Moreover, its action is aimed at regulating mineral metabolism.

The action of Calciferol is reflected even in its name. It regulates calcium metabolism. How Calciferol enhances the absorption of calcium ions in the intestine. And as a hormone, it ensures the reabsorption (reabsorption) of calcium in the renal tubules and stimulates the synthesis in the intestine of a specific carrier protein that actively transports calcium to bone tissue.

True, it is not the hormone itself that acts as a hormone, but its active metabolites. In addition to calcium, it regulates the exchange of magnesium and phosphorus - enhances the absorption of magnesium ions and phosphorus salts, phosphates in the intestine.

But the most physiologically significant function of Calciferol is calcium metabolism. Under its action, calcium is transported from the blood plasma into bone tissue and dental dentin. This ensures the growth and strength of bones and teeth, the correct formation of the skeleton in childhood and adolescence. In children and adults, thanks to it, bone fragments grow together (consolidate) faster after fractures. At the same time, Calciferol works in such a way that calcium is deposited only in the right places, and pathological bone elements in the form of osteophytes and bone growths are not formed.

Strengthening bone tissue is achieved not only due to the deposition of calcium in it, but also due to the synthesis of collagen. This protein (more precisely, a complex of proteins) ensures the strength of the connective tissue of the skin, bones, ligaments and tendons. In addition, Vit. D increases muscle strength and endurance. After all, calcium is the element without which muscle contractions are impossible.

However, the activity of Calciferol is not limited to the musculoskeletal system alone. Due to its participation in the metabolism of calcium, magnesium, phosphorus, vit. D has a positive effect on other organs and systems:

• The cardiovascular system
  Regulates the strength of heart contractions and blood pressure (BP). Prevents the development of hypertension with high blood pressure in pregnant women. It has an anti-atherosclerotic effect, prevents myocardial ischemia (insufficient blood flow through the coronary arteries to the heart muscle).

• The immune system
  Strengthens the immune system, forms resistance (resistance) to various types of infections.

• Blood
  Regulates blood clotting.

• Skin and appendages
  Provides strength and elasticity to skin and hair. Reduces the severity of skin diseases - psoriasis, dermatitis.

• Nervous system
  Participates in the synthesis of myelin sheaths of nerve fibers. Thus, it promotes the conduction of impulses along these fibers. Stimulates thinking, attention, memory.

• Endocrine system
  Regulates the activity of the thyroid gland. Stimulates the synthesis of insulin by the pancreas, and thereby reduces blood sugar levels and prevents the development of diabetes.

• Reproductive system
  Strengthens male erection and forms libido in both sexes. In pregnant women, it ensures the formation of the fetal skeletal system. During childbirth, it stimulates labor and helps a woman give birth to a healthy child on her own, without a caesarean section. In the future, thanks to it, the correct formation of bones and timely growth of teeth in the child occurs. Along with these physiological effects, Calciferol is involved in decoding information encrypted in DNA and RNA, which is of great importance in the synthesis of protein compounds and many biologically active substances of the non-protein series. Under the influence of Vit. D fats are burned. Increased breakdown of fatty compounds leads to weight loss. It is also an oncoprotector. Prevents the development of many types of malignant tumors, in particular leukemia, brain cancer, breast cancer, prostate cancer and ovarian cancer.

Daily norm

In this table, 1 IU (international unit) corresponds to 0.025 mcg of vit. D

Causes and signs of deficiency

Since vitamin D3 is activated in the skin under the influence of sunlight, insufficient insolation will contribute to vitamin D3 deficiency. Therefore, autumn winter time, living in the Far North, with a long polar night, will be accompanied by its deficiency. Due to insufficient insolation, vitamin D deficiency is quite often observed in patients who are bedridden for a long time, in people who work in dark rooms or underground (subway workers, miners).

But it’s not just a matter of quantity, but also the quality of solar radiation. The precursor, provitamin D3, is 7-dehydrocholesterol. It is found in the lower connective tissue layers of the skin, in the dermis. And only the upper, epidermal layers of the skin are permeable to sunlight.

Provitamin 7-dehydrocholesterol is capable of absorbing only a narrow spectrum of radiation with a wavelength of 290-320 nm. It is this part of the sunlight that is absorbed by smog, which consists of exhaust gases and industrial emissions.

Consequently, living in polluted regions, in large cities, will also contribute to vitamin D deficiency. Since 7-dehydrocholesterol is a kind of raw material for vitamin D. D, then its initial deficiency will also lead to hypovitaminosis D.

A decrease in the amount of 7-dihydrocholesterol is observed in skin diseases affecting a large area of ​​skin, in some metabolic disorders, as well as in old age and in people with dark skin. Therefore, belonging to the Negroid race also predisposes to vitamin D deficiency.

Vit. D is absorbed in the small intestine in the presence of dietary fats, which are emulsified by the action of bile. Therefore, a deficiency of this vitamin will be promoted by:

• inflammatory diseases of the small intestine (enteritis)
• liver disease, gallbladder, liver failure.
• insufficient dietary fat intake, vegetarianism
• vitamin deficiency D in food products.

Another factor predisposing to vitamin D deficiency is pregnancy. Bearing a fetus is accompanied by increased consumption of this vitamin. The same thing happens with severe injuries with bone fractures.

With a deficiency of vit. D calcium, even in sufficient quantities supplied from outside with food, will not be absorbed in the body. A decrease in calcium levels in the blood plasma activates the parathyroid glands, which synthesize parathyroid hormone. Under the influence of this hormone, calcium is washed out of the bones.

A pathological condition such as osteoporosis develops with osteomalacia (softening of bones) and a decrease in their density. Persons with osteoporosis are susceptible to fractures of long bones, which in some cases can be spontaneous, i.e., spontaneous, without a traumatic agent. Fractures take a long time to heal, and specific growths form on bone defects. Teeth fall out and caries develops.

In addition to fractures, osteoporosis is manifested by destructive processes in the spine such as scoliosis (curvature), deforming osteoarthritis with herniated intervertebral discs. Due to disruption of collagen synthesis, the strength of the ligamentous apparatus is lost, muscle weakness and low tolerance to physical activity appear. Such patients often suffer from joint diseases, arthrosis and arthritis.

Vitamin D deficiency in children manifests itself as rickets. Rickets is characterized by osteomalacia with curvature of the limbs, spine, the appearance of costal growths (the so-called rachitic rosary), and an altered configuration of the skull with enlarged frontal and parietal tubercles. At the same time, there is a lag not only in physical, but also in mental development.

Currently, rickets in children is uncommon. However, hypovitaminosis D in infants is still quite common. The following signs are noted:

• hip dysplasia secondary to osteomalacia
• late fusion of fontanelles with altered skull configuration
• anxiety, poor sleep
• atopic dermatitis
• late teething with abnormal bite formation
• late sitting and walking skills.

Causes of hypovitaminosis D in a child:

• prematurity
• complicated childbirth
• early transition to artificial feeding.

Babies born in the autumn-winter-spring period, from October to May, have a higher risk of hypovitaminosis D and related disorders than their peers born in the summer.

In adults, along with changes in the musculoskeletal system, calcium, magnesium, and phosphate deficiency is accompanied by other symptoms:

• insomnia
• general weakness
• burning sensation in the mouth and oropharynx
• loss of appetite
• myocardial dystrophy
• heart rhythm disturbances
• increased sweating.

In addition, hypovitaminosis D in adults is associated with diseases such as diabetes mellitus, myocardial infarction, psoriasis, multiple sclerosis, and malignant neoplasms.

Sources of income, which products contain

D2 enters the body as part of synthetic drugs and food additives, and D3 is formed in the skin under the influence of sunlight or also comes from food and medications.

The table shows that the “record holders” in terms of content, like other fat-soluble vitamins, are cod liver and fish oil. There is quite a lot of it in other animal products - in eggs, in milk and dairy products, as well as in fish. Plant foods, with the exception of mushrooms, on the contrary, practically do not contain it. A small amount is found in vegetables, potatoes, herbs, and grains.

When preparing food, it is important to follow some rules:

• do not freeze meat and fish
• If you do freeze it, cook it immediately after defrosting.
• When cooking, place in boiling water, not cold
• avoid overcooking
• Do not reheat cooked dishes multiple times.

Vit. D is one of the few synthesized in the human body. It’s not for nothing that they called it sunny. Insolation promotes the conversion of 7-dehydrocholesterol into Cholecalciferol. But the main thing here is not to overdo it. For complete synthesis, a 15-minute exposure to the sun is enough. Besides the greatest amount of light with the required wavelength of 290-320 nm is observed in the morning and evening hours.

And prolonged “frying” of your own body during the day in the summer heat is not only useless, but also harmful. Firstly, tanning reduces the supply of 7-dehydrocholesterol. And secondly, the risk of getting skin cancer increases.

Synthetic analogues

For therapeutic and prophylactic purposes, the following dosage forms of Vit are produced. D:

• Natural fish oil
• Cholecalciferol
• Ergocalciferol
• Alfacalcitol is a synthetic form of Ergocalciferol.
• Calcitriol – natural active Cholecalciferol
• Calcipotriol – synthetic Calcitriol.

The drugs are available in various dosage forms: dragees, capsules, oil, alcohol and aqueous solutions for oral administration, as well as in the form of oil solutions for intramuscular administration. Administers intravenous medications Vit. D, like other oil solutions, is not allowed.

Medicines with vit. D do not necessarily bear the name of the active substance. They may have patented names Vigantol, Oxidevit, Aquadetrim, Videhol. This vitamin is part of the complex preparations Structum, Vitrum, Pikovit, Polivit, and many others.

Indications for use

For adults, Vit. D are indicated for the following diseases and pathological conditions:

• pathology of the musculoskeletal system: bone fractures with delayed consolidation of fragments, osteoporosis and osteomalacia, osteomyelitis, arthritis
• Gastrointestinal diseases: chronic atrophic gastritis, chronic enteritis and enterocolitis, chronic pancreatitis
• menopausal syndrome in women
• tuberculosis
• excessive or insufficient function of the parathyroid glands - hyper or hypoparathyroidism
• systemic lupus erythematosus.

As part of complex therapy for psoriasis, Calcipotriol preparations are prescribed in the form of ointments and creams (Glenriaz, Daivobet, Daivonex) to treat the affected areas.

It is prescribed to children for the prevention and treatment of rickets. For this purpose, oil drops (Vigantol, Minisan, Aquadetrim) can be taken by babies from the first weeks of life. Not only for newborns, but also for pregnant and lactating women, it is recommended to take it for preventive purposes.

Metabolism

As already mentioned, D2 and D3 are not complete vitamins. These are provitamins from which active compounds are formed during metabolic reactions. Food and medicinal vit. D is absorbed in the small intestine. After absorption, calciferols are incorporated into chylomicrons. These substances are synthesized in the intestines and are lipoproteins, compounds of protein and fat (lipid) compounds.

Since lipids are required for the formation of chylomicrons, fatty foods facilitate absorption. The other part is absorbed in combination with protein-carbohydrate compounds and glycoproteins. In this form it enters the liver. Vit. D3, formed in the skin under the influence of sunlight, is also carried into the liver through the bloodstream.

In the liver, Cholecalciferol and Ergocalciferol undergo enzymatic hydroxylation to form the transport forms 25-hydroxycholecalciferol and 25-hydroxyergocalciferol. These substances bind to a specific calciferol-binding protein and are sent to the kidneys. Here, in the course of further enzymatic reactions, 1,25-dihydroxycalciferols or Calcitriol are formed from them. This is the active metabolite of vitamin D, which regulates the metabolism of calcium, magnesium and phosphates.

25-hydroxycholecalciferol, 25-hydroxyergocalciferol and 1,25-dihydroxycalciferol undergo enzymatic degradation. It is excreted from the body in feces unchanged or in the form of metabolites. But, since it is fat-soluble, it can accumulate in fatty tissues and in the liver.

Interaction with other drugs

Facilitates the absorption of drugs containing calcium, magnesium and phosphates in the intestines.

Synthetic corticosteroids promote the removal of calciferols from the body and slow down the absorption of calcium. This is fraught with rickets and osteoporosis with osteomalacia.

Saline laxatives interfere with the absorption of vitamin D and calcium salts.

Antiatherosclerotic drugs that lower cholesterol levels impair absorption. Therefore, these medications and synthetic calciferols need to be taken at different times.

Antacids (which reduce the acidity of gastric juice), anti-tuberculosis drugs and psychotropic drugs from the barbiturate group also negatively affect metabolism.

Calcium is a kind of competitor to iron. Therefore, the absorption of calcium in the intestine under the influence of vit. D leads to inhibition of iron absorption.

Vitamins of group D (calciferols) include steroid compounds with antirachitic activity. The most important representatives of this group are cholecalciferol (vitamin D3) and ergocalciferol (vitamin D2).

Calciferols are sensitive to light and atmospheric oxygen, especially when heated. Calciferols are formed as a result of photoisomerization of the corresponding provitamins (7-dehydrocholesterol) under the action of solar or artificial ultraviolet radiation with a wavelength of 280-320 nm on the skin.

In addition, calciferols enter the body with food. Vitamin D is found mainly in animal products. It is rich in fish liver oil. Found in very small quantities in plant products.

Calciferol units

Vitamin D activity is measured in international units (IU).

1 ME corresponds to 0.025 μg of ergo- or cholecalciferol.

1 mcg of vitamin = 40 IU.

Sources

Traditional food sources of vitamin D are cod liver, fish, fish oil, liver, eggs, and butter.

Physiological significance

The main functions of vitamin D in the body are related to maintaining calcium and phosphorus homeostasis and carrying out the processes of bone tissue mineralization.

The main processes in which vitamin D plays an important role are:

Absorption of calcium and phosphorus in the intestine,
- mobilization of calcium from skeletal bones,
- reabsorption of calcium in the renal tubules.

Calciferols are absorbed in the small intestine and enter the liver, where they are converted into 25-hydroxycholecalciferol (25OHD3) and 25-hydroxyergocalciferol (25OHD2), which enter and are determined by laboratory methods in the blood.

Calciferols can be deposited (accumulated) in adipose tissue. They are excreted from the body mainly in feces.

The need for vitamin D is increased in people lacking ultraviolet radiation:

Living in high latitudes
- residents of regions with high air pollution,
- working night shifts or simply leading a nocturnal lifestyle,
- bedridden patients who do not spend time outdoors.
In people with dark skin (black race, tanned people), the synthesis of vitamin D in the skin may be reduced. The same can be said about older people (their ability to convert provitamins into vitamin D decreases).
Pregnant and lactating women have an increased need for vitamin D.

Daily requirement

Table. Norms of physiological requirement for vitamin D depending on age in Russia [MR 2.3.1.2432-08]

The upper permissible level of vitamin D intake for adults is 15 mcg per day (“Unified sanitary-epidemiological and hygienic requirements for goods subject to sanitary-epidemiological supervision (control)” of the EurAsEC Customs Union) and 50 mcg per day according to the “Norms for physiological energy needs and nutrients for different groups. population of the Russian Federation. Methodological recommendations MR 2.3.1.2432-08.”

Symptoms of hypovitaminosis

A typical manifestation of vitamin D deficiency is rickets. Initially, nonspecific manifestations of deficiency are observed: increased irritability, general weakness, sweating, for young children - delayed teething, a tendency to bronchitis, slow ossification of the fontanelles.

In temperate and northern climates, the main cause of rickets is insufficient sun exposure of the child. Another cause of rickets is a lack of vitamin D in the diet. Vitamin deficiency leads to soft bones and characteristic deformities.

In adolescents and adults, clinical manifestations of deficiency include nagging pain in the lower extremities, lethargy, and fatigue. Changes in the bone diaphysis, osteomalacia, and osteoporosis develop. To assess the supply of vitamin D, the concentration of calcium, phosphorus and 25OHD in the blood serum is examined.

Signs of vitamin D deficiency include:

In children
• increased irritability
• motor restlessness
• general weakness
• sweating
• delayed teething and ossification of fontanelles
• rickets
• spasmophilia
• tendency to respiratory diseases.

In adults
• lethargy, fatigue
• osteoporosis, crumbling teeth
• pain in the pelvic bones, duck gait, lameness
• muscle pain.

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Toxicity

Vitamin D in doses exceeding the physiological requirement by 200-1000 times is highly toxic, causing a state of hypervitaminosis with hypercalcemia and calcification of the tissues of internal organs (kidneys, aorta, heart), which leads to disruption of their functions.

Large doses disrupt the activity of the central and autonomic nervous systems and the cardiovascular system.

Intoxication when taking from 1 to several million IU of vitamin D occurs with general weakness, headache, joint, bone and muscle pain, numbness of the arms and legs, constipation, fever, arterial hypertension, conjunctivitis, hemorrhages on the skin; convulsions are possible.

* dietary supplement. NOT A MEDICINE

Everyone knows that vitamin D is necessary for the body to strengthen bones. But not everyone knows about its other properties. Thus, in recent years it has become clear that it takes an active part in the formation of immunity; the incidence of viral and bacterial infections, as well as the development of autoimmune and oncological processes, depends on it. Experts believe that not all the properties and functions of vitamin D have been studied, and almost half of the population is deficient.

What is vitamin D

Under the general name “Vitamin D”, or “calciferol” (ergocalciferol - the Latin name), several fat-soluble organic substances are known. The most important vitamins for the human body are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). They are actually provitamins that must undergo activation to become steroid hormones.

There are interesting facts in the history of the discovery of vitamin D: it is related to vitamin A (retinyl). The latter was isolated from fish oil in the early 20th century. It was soon discovered by chance that dogs fed fish oil did not develop rickets. At that time, this disease was one of the main problems in pediatrics.

This has led to the idea that the disease rickets is associated with retinol deficiency. But the American scientist Elmer McCollum, who made the discovery of retinol, refuted this hypothesis. He conducted an experiment with dogs suffering from rickets, and discovered that it was possible to cure rickets with some new substance, since the dogs received a remedy with neutralized retinol. So, in 1922, a new vitamin was discovered, which was named vitamin D after the 4th letter of the Latin alphabet.

A year later, it was found that if food is irradiated with ultraviolet rays, the amount of vitamin D increases, that is, UV rays are its source. Here's the story.

Varieties of calciferols

Vitamins of group D (C 27 H 44 O 3) are sterols in structure.

The following vitamers or forms of vitamin D are distinguished:

	D1 Formula: C 56 H 88 O 2 Contains 2 components: lumisterol and ergocalciferol, not found in the human body. Obtained only artificially. It does not play a big role in medicine.
	D 2(ergocalciferol) Chemical formula: C28H44O It enters the body with plant foods, is included in a number of dietary supplements, and has a slight effect on the content of calciferol in the blood.
	D3(cholecalciferol or colecalciferol) Formula: C27H44O The most active form. Sources: food of animal origin and sunlight (produced in the skin under the influence of ultraviolet radiation - UVR).
	D4(dehydrocholesterol) Chemical formula: C 28 H 46 O Located in the epidermis, under the influence of ultraviolet radiation it turns into D3.
	D5(sitocalciferol) Formula: C 29 H 48 O Characteristics: refers to synthetic analogues of vitamin D3, the least toxic form. Interesting facts: vitamin D5 is used to fight cancer. Found naturally in wheat oil. It was first synthesized in Chicago.
	D6(stigmacalciferol) Chemical formula: C 29 H 46 O Isolated from plants. Vitamin D 6 is at the stage of studying its structure and characteristics.

How it works in the body

You can understand the benefits of vitamin D by studying its action. Below is a description of the main functions of vitamin D:

• the main thing vitamin D is responsible for is the absorption of calcium and phosphorus in the duodenum and reabsorption in the kidneys; promotes the growth and strengthening of bone tissue and tooth enamel in children;
• participates in activating the immune system by stimulating protein synthesis; deficiency of vitamins D leads to frequent colds and chronic infectious and inflammatory processes in the lungs, kidneys, etc.; Immunity disorders lead to the development of autoimmune (with allergies to one’s own tissues) inflammatory processes (rheumatoid arthritis, etc.);
• suppresses the mechanism of development of demyelinating diseases of the nervous system, including multiple sclerosis, most often of autoimmune origin; myelin is a sheath that covers the nerves and prevents disturbances in the transmission of nerve impulses;
• prevents the development of cancer by suppressing the growth of tumor cells; this effect of vitamin D was noted in a WHO report in 2008; prevents the development of diabetes and obesity - has a metabolic effect;
• regulates blood clotting;
• normalizes blood pressure (BP), inhibits the development of atherosclerosis, which is the prevention of coronary heart disease and atherosclerosis of the peripheral arteries of the extremities with the possible development of gangrene;
• stimulates collagen synthesis, strengthens bones and teeth, preserves the youth of the skin epidermis; the role of vitamin D in this process is irreplaceable;
• promotes the formation of insulin, lowering blood sugar; regulates carbohydrate metabolism;
• normalizes fat metabolism, reduces body weight.
• stimulates the mechanism of synthesis of male sex hormones, eliminates the phenomena of impotence;
• participates in the maturation of the egg in women;
• helps improve vision;
• suppresses the aging process - the role of vitamin D in this process has not yet been fully studied.

Vitamin D is especially necessary for infants and the elderly. Since infants (especially newborns) rarely sunbathe and receive very little calciferol from food during breastfeeding, they are prescribed additional intake in the form of medications. Baby food is also almost always fortified with calciferol.

There is no doubt that vitamin D is beneficial for older people, whose ability to absorb this biologically active compound is often impaired, so additional intake is required.

Important: it is necessary to accurately calculate the dose of the drug, since only a deficiency, but also an overdose, is dangerous. This must be done by a doctor, otherwise irreparable harm may be caused to the body.

Metabolism of calciferols in the human body (metabolism)

Vitamin D metabolism is complex. Vitamin D2 is not synthesized in the human body. It comes with plant foods in small quantities. Dietary supplements (dietary supplements) with synthetic ergocalciferol are also produced, which also slightly increase its level in the body.

Vitamin D3 (cholecalciferol) is synthesized in the skin when exposed to sunlight. It also enters the body with animal food. Cholecalciferol contained in dietary supplements is of animal origin.

In order for provitamins to be involved in biological processes, they must undergo double activation in the human body. Briefly it looks like this:

• in the liver, provitamins are exposed to enzymes and converted into calcidiol (25 (OH)D); This substance is used to judge the amount of vitamin D in the body;
• the second stage of activation takes place in the kidneys, the active form of vitamin D is formed, the steroid hormone calcitriol (1.25 (OH)2D);
• the effect of calcitriol on the intestines is the stimulation of protein production for calcium transport; it also has an effect on the smooth muscles of the urinary tract, enhancing the reabsorption of calcium.

Regulation of the production of activating enzymes occurs mainly under the influence of parathyroid hormone (PTH). The concentration of PTH depends on the content of calcitriol, phosphorus and calcium in the body: the more of these substances, the less PTH and enzymes the body needs to replenish vitamin D.

Normalization of enzyme synthesis also affects the production of hormones: female and male sex hormones, thyroid gland, pituitary gland, etc. The synthesis of enzymes is suppressed when they are in excess in the body.

Vitamin D in its active form (calcitriol) suppresses tumor formation.

Subsequently, the active form of vitamin D is converted by enzymes into an inactive form (metabolite calcitroic acid) and is excreted from the body with bile. The question of what else vitamin D is involved in is under study.

Vitamin balance

The importance of vitamin D for humans can hardly be overestimated, so you should constantly replenish its supply in the body. Daily value for different age groups (measurements in units of mcg or IU: 1 mcg = 40 IU):

UNIT CONVERTER: VITAMIN D

Cholecalciferol (D3)/ergocalciferol (D2)

Form of substance

IU mg µg g

Decimal places as a result

Convert

Conversion of IU ⇄ g/mg/mcg (developed by pharmacists and doctors based on reliable data)

Increased daily amounts of vitamin D will be required mainly for people:

• those living in the North, where there is little sun;
• living in environmentally unfavorable areas;
• working at night;
• bedridden patients who rarely spend time in the sun;
• patients with diseases of the stomach and intestines - with these diseases (vitamin D is poorly absorbed;
• elderly people prone to colds;
• during pregnancy and lactation.

The maximum daily dose is 15 mcg (600 IU). Some experts believe that the human body requires much larger doses of vitamin D, increasing the maximum daily dose to 4000 IU or more. But so far the World Health Organization (WHO) has not made such recommendations: calciferols are under study.

Vitamin deficiency (hypovitaminosis)

In recent years, experts have been actively discussing the question of why the body needs vitamin D. Special attention has been paid to hypovitaminosis, since it is believed that half of the globe has it. In northern latitudes, this occurs due to a lack of sunlight, and in southern latitudes, due to the fact that the production of vitamin D is impaired in dark skin. This becomes a serious problem, so significant is the effect of calciferols on the body. And if previously the main problem was considered to be its deficiency in children, today deficiency in adults is no less important.

The cause of vitamin deficiency may be:

• constantly wearing clothing that covers the body;
• long-term use of sunscreen (it is not always useful);
• malabsorption in the small intestine due to inflammatory processes - duodenitis, enteritis;
• violation of bile formation (primary activation of provitamin suffers) against the background of chronic diseases of the liver and biliary tract - hepatitis, cholecystitis, cholangitis;
• poor nutrition - vegetarianism (some people believe that they have enough plant foods), any defects leading to digestive disorders;
• sedentary lifestyle, excess weight;
• hormonal disorders.

Signs of deficiency and possible consequences in adults

Vitamin D is very important for humans; when it is deficient in the body, children develop rickets, and adults develop osteoporosis and various diseases of internal organs and systems.

The first symptoms of deficiency may be weakness, sweating, irritability, decreased performance and sleep disturbances (insomnia at night and drowsiness during the day). Appetite decreases, dryness and burning in the mouth appear.

Due to immunity disorders, people with a deficiency often suffer from colds, complicated by chronic infectious and inflammatory processes. Immunity disorders can cause the development of autoimmune diseases and cancer.

Often with this condition, pain occurs in the joints and spine, since calciferol deficiency is associated with impaired synthesis of connective tissue in the body. The ligaments of the joints, the cartilage covering the articular surfaces and forming the basis of the intervertebral discs, are affected. A lack of collagen affects the skin - it ages quickly. This moment is well reflected in the video of the program “Live Healthy!”

Bones become brittle and the risk of fractures increases. The calcium content in the blood increases. Teeth decay due to insufficient calcium absorption.

Impaired conduction of nerve impulses leads to paresis of the smooth muscles of the intestine and its obstruction. This can also cause damage to skeletal muscles, the development of multiple sclerosis, and visual impairment.

Vitamin D deficiency also affects the reproductive system. In women, the process of egg maturation is disrupted, and in men, testosterone synthesis decreases, which affects spermatogenesis and potency.

Timely correction of vitamin D deficiency will prevent all these disorders. If this is not done, the consequences will affect not only the state of the skeletal system, but also the state of many other organs and systems of the body.

Watch the video of the program “Live Healthy!” with Elena Malysheva:

Signs of deficiency and possible consequences in children

In children, a low level of blood calciferols manifests itself in the form of diseases such as rickets and spasmophilia, which is why the vitamin is called antirachitic.

Knowing what vitamin D affects, it is easy to understand what results its deficiency will lead to. The lack of calciferols plays a role in disrupting the metabolism of minerals and their absorption by tissues.

The first signs of rickets most often appear in a child at the age of 3–4 months. The disease occurs in four stages:

1. The initial stage lasts from several weeks to 2-3 months. The first signs of the disease are associated with the nervous system: the baby becomes too excitable, flinches from strong sounds, sleep and appetite are disturbed. The main signs of the initial stage of rickets include baldness of the back of the head: with excessive sweating, the baby feels itching and constantly turns his head, rubbing it on the pillow, which causes a bald spot to form. The immune system suffers, and colds develop more often. The initial stage of rickets occurs to one degree or another in most children. But everyone is prescribed treatment in the form of oral vitamin D in a timely manner.
2. Heat stage. Symptoms associated with damage to the musculoskeletal system appear. First, this can be noticed on the head: the cranial bones become soft, this is especially noticeable along the edges of the large and small fontanelles. The head often changes its shape. The sternum protrudes forward and the chest takes on the shape of a chicken. The ribs thicken and rachitic rosaries appear. They are easy to feel, and in a thin baby they can be seen. If he does not receive treatment, after six months the legs become bent and take on an O- or X-shape. Rachitic bracelets appear on the arms and legs, descriptions of which were made by pediatricians back in the century before last. The baby is lagging behind in physical development.
3. Recovery stage. All symptoms disappear gradually with treatment or with the onset of the warm season, when the baby spends a lot of time in the sun.
4. Stage of residual effects. It can last up to 2 – 3 years. After severe rickets, some bone changes may remain for life.

Against the background of rickets, sometimes there is a sharp decrease in the calcium content in the blood plasma, which leads to the development of seizures. This complication is called spasmophilia. It is rare today, but a few decades ago it was quite common in bottle-fed infants. A description of spasmophilia can be seen in the works of pediatricians of the 19th and 20th centuries. Baby food products enriched with vitamins and minerals helped change the situation.

Watch the video of Dr. Komarovsky, where he briefly talks about rickets and its treatment:

How to compensate for vitamin deficiency

• sunbathing in the sun (possibly in a solarium);
• introducing foods rich in vitamin D into your diet; this is the safest type of correction, as it is never accompanied by overdose and is well absorbed by the body;
• folk remedies; infusions of parsley and dill will help; not all experts recognize the effectiveness of folk remedies;
• taking medications and dietary supplements with calciferols; it is better to do this as prescribed and under the supervision of a doctor, since an overdose and the development of hypervitaminosis are possible.

Hypervitaminosis (excess)

Hypervitaminosis D is even more dangerous than hypovitaminosis, as it can cause serious harm to the body. Old doctors believed that it was better to have mild rickets than to overdose on vitamin D.

Signs of excess vitamin D in the body

There are acute and chronic intoxication with calciferol.

Acute intoxication may develop in children if vitamin D is taken in high dosages for several weeks or if there is hypersensitivity to it. The following symptoms appear:

• lethargy, lack of appetite, constipation or diarrhea, nausea, vomiting; this means that fluid loss can be accompanied by such a dangerous condition as dehydration (exicosis);
• headaches, muscle and joint pain, sometimes cramps;
• increased body temperature, blood pressure (BP), low pulse, difficulty breathing.

Chronic intoxication occurs against the background of long-term (at least six months) use of the vitamin in therapeutic doses. Symptoms:

• decreased appetite, slowly increasing lethargy and decreased or no weight gain;
• increased calcium content in bones and changes in bone tissue: early fusion of the large fontanel, ossification of the sutures of the skull bones, partial ossification of the growth zone of long bones;
• increased calcium levels in the blood and its deposition in the walls of blood vessels, in the kidneys, heart, lungs and other organs, which means their functions will suffer.

There are 3 degrees of severity of intoxication when vitamin D is in excess: mild (without toxicosis), moderate (with moderate toxicosis) and severe (with severe toxicosis).

Possible consequences of excess

Mild degrees of intoxication pass without consequences, but after severe ones the consequences can remain for life. Calcium deposition in the walls of blood vessels and internal organs plays a role, which leads to disruption of their functioning. Children often develop chronic pyelonephritis and irregular teething. In adults, hypervitaminosis causes an increase in blood pressure (BP) and contributes to the development of cardiosclerosis, accompanied by cardiac arrhythmia.

Treatment of overdose

If an overdose of calciferol is suspected, it is better to hospitalize the baby. In the hospital, depending on the severity of intoxication, he is prescribed intravenous administration of medicinal solutions with the simultaneous administration of diuretics (forced diuresis) in order to remove excess calcium.

In severe cases, hormonal therapy is prescribed: glucocorticoid hormones inhibit the reabsorption of calcium in the kidneys.

Indications for use

Medicines and dietary supplements that contain vitamin D should be prescribed by a doctor. The doctor will also tell you what vitamin D is and how to choose the most suitable dosage form.

When prescribing a correction, it is taken into account what vitamin D is responsible for and whether it really needs to be increased. Taking calciferols helps with the following diseases and conditions:

• for the prevention and treatment of rickets;
• spasmophilia;
• softening of bones (osteomalacia) of various origins;
• diseases of the osteoarticular system against the background of mineral metabolism disorders;
• insufficient calcium content (hypokalemia) in the blood;
• convulsions due to hypokalemia;
• osteoporosis (depletion of bones in calcium), including during menopause; vitamin D is especially important for people over 60 years of age precisely because of the risk of developing osteoporosis;
• with slow healing of bones after a fracture;
• with massive caries due to demineralization (loss of calcium) of tooth enamel;
• with frequent colds due to vitamin deficiency.

Each drug has its own contraindications for taking vitamin D.

Should I give it to a newborn?

Why give vitamin D to a newborn? Pediatricians and neonatologists (doctors who treat infants in the first month of life) around the world recommend that all newborns take vitamin D in an aqueous solution. It helps:

• skeletal formation;
• proper teething;
• normal functioning of the nervous system;
• development of visual organs;
• normal functioning of the cardiovascular system;
• formation of strong immunity and prevention of infections;
• prevention of rickets.

How to give to children

It is recommended that newborns be given vitamin D in the form of cholecalciferol. Usually a prophylactic dose of 400 - 500 IU per day in the form of an aqueous solution is sufficient. For premature babies, the dosage may be increased. For bottle-fed children, the dosage is selected individually, taking into account the calciferol content in the feeding mixture.

Sometimes higher dosages of up to 600 IU are useful, for example, in northern regions or in areas with unfavorable environmental conditions. Taking the vitamin in high dosage is prescribed to a nursing mother, in which case the baby receives calciferol with her milk.

In the summer, vitamin D may not be given or given in a lower dosage. It should also be taken into account that dark-skinned children need a higher dosage of the vitamin, since it is produced less well in their skin.

Therapeutic dosages are selected by doctors individually in IU (regardless of the name of the drug).

Effect of summer time (active sun)

Under the influence of ultraviolet rays, vitamin D (cholecalciferol) is formed in the skin. Regular exposure to fresh air during the summer increases the supply of vitamin D. You just need to know that clothing and sunscreen interfere with this process.

To replenish cholecalciferol reserves in the body, you need to spend 30 minutes in the daytime sun every day. But in a very hot sun you can get burned, so you need to start with 5 - 7 minutes, gradually reaching the desired time.

Is it possible to be allergic to a vitamin?

Allergic reactions develop to any medications. Vitamin D (calciferol) in an oil solution more often causes allergic reactions. Aqueous solutions very rarely cause allergies and are better tolerated by adults and children.

The best natural sources (table)

The best sources of the vitamin are fatty sea fish and fish oil. Here is how its content in various products looks in the table:

Vitamin D calciferol is found in smaller quantities in plant foods. Most of them are found in various types of mushrooms: 100 g of wild mushrooms contain 10 IU. It is also present in cereals (for example, oatmeal), parsley, dill, yeast, and oranges. A varied diet will benefit you.

Vitamin D for humans is produced in different dosage forms: in the form of capsules and tablets for oral administration, oral solution, chewable tablets and even ointments. In addition, such types as combined products are produced that contain vitamin D and calcium.

Medicines in capsules

Vitamin D for adults is available in capsules for oral administration. These drugs include Alpha D3 Teva, Osteotriol, Rocaltrol. On the iHerb website you can purchase high-quality American-made dietary supplements with vitamin D. The peculiarity of these dietary supplements is their high dosages, so before taking them, you should consult your doctor, get tested for the content of calciferols in the blood plasma and adhere to the dosages given in the recommendations.

Preparations in the form of a solution

Vitamins D2 and D3 (Ergocalciferol, Vigantol, Videhol) are produced in the form of an oil solution, and only vitamin D3 (Aquadetrim, Complivit Aqua D3) in the form of an aqueous solution. These dosage forms are more often prescribed to children. Most specialists prescribe aqueous solutions of cholecalciferol to children. On the iHerb website you can purchase California Gold Nutrition dietary supplement with an aqueous solution of vitamin D3 for infants. Above in the text, we have already explained why babies need vitamin D: to prevent rickets. The dose of the vitamin is selected by the doctor, who also treats rickets under the supervision of laboratory tests.

Chewable medications

Vitamin D for adults and schoolchildren is also available in chewable tablets. They can be purchased at your local pharmacy (Ultra-D Chewable) or on the iHerb website (Vitamin D3, Chewable, Orange Flavor, 400 IU, 110 Tablets 21st Century). Like all other drugs, they are best used as prescribed by a doctor.

Calcium with vitamin D

The most famous combination drug (vitamin D for adults with calcium) is Calcium D3 Nycomed, which is available in chewable tablets. Analogs are drugs with the following names: Complivit Calcium D3, Vitrum Calcium with vitamin D3, Alfadol-Sa, Natekal D3, Kalcemin Advance. Dietary supplements with these active substances can also be purchased on the iHerb website.

Why is vitamin D with calcium needed: combined preparations improve phosphorus-calcium metabolism, normalize the mineralization of bones and teeth, immunity, and the conductivity of neuromuscular impulses.

Vitamin D ointment/cream

The composition of ointments and creams includes calcipotriol, a synthetic analogue of cholecalciferol metabolites (Calcipotriol, Daivonex, Psorkutan, Glenriaz, Daivobet). Silkis ointment contains the calciferol metabolite calcitriol.

These drugs have a pronounced antipsoriatic effect. They successfully treat psoriasis, and the medicinal effect develops gradually over 1 to 3 weeks of use. Helps normalize the condition of the epidermis. But patients with psoriasis sometimes do not understand what vitamin D does and what benefits it brings. For specialists, the question of what vitamin D does for the treatment of psoriasis does not arise today: most dermatologists have been convinced in practice of the high effectiveness of these drugs.

How to choose a drug

It is best to entrust the choice of medication and its dosage to a doctor, since different medications are suitable for patients of different ages with different concomitant diseases.

Where to buy vitamins cheaply and at a discount

Now that we have found out why vitamin D is needed, it’s time to start buying it. It is convenient to buy vitamins in the iHerb online store (iHerb.com). You just need to first agree with your doctor on the dosage and dosage form of the drug. IHerb has a wide range of high-quality dietary supplements at a price 1.5-2 times lower than in a pharmacy. Why overpay?

Instructions for the use of drugs for prevention and treatment

The vitamin is taken in any dosage form for internal use immediately after or during a meal once a day. Cream or ointment is applied twice a day. To do this, take the cream, squeeze it onto cleanly washed hands and apply it to the affected areas of the skin.

When asked what preventive doses of vitamin D provide, the doctor gives an individual answer, since everything depends on the patient’s condition and age. Therefore, preventive doses do not always coincide with the daily requirement of a particular age:

Preventive administration of calciferols is carried out in intermittent courses: a month of administration - a two-week break.

Therapeutic dosages of calciferols are prescribed by the doctor individually. With long-term (more than 6 months) use of the drug, a blood test for vitamin D must be performed every three months. The World Health Organization (WHO) has not yet made clear recommendations on the dosage of calciferols.

Vitamin D combines well with vitamins A, E, C, B1, B2, B5 and B6, as well as calcium and magnesium.

How to check vitamin levels in adults and children

The level of vitamin D in the human body is determined by the content of calcidiol (25 (OH)D) in the blood plasma, a product that is formed during the primary activation of provitamins D2 and D3. Measurements are carried out in ng/ml. This is the most stable indicator that reflects the true state of affairs. Analysis of results:

To confirm the diagnosis of hypo- or hypervitaminosis, it is recommended to simultaneously check the calcium and phosphorus levels in the blood plasma.

The analysis is taken in the morning on an empty stomach. A high level of indicators can be:

• with an overdose of vitamin D;
• with prolonged exposure to the sun or solarium;
• when taking bisphosphonates, medications used to treat osteoporosis.

A low level of indicators is observed in the following conditions:

• violation of vitamin absorption in the intestines;
• disruption of bile formation processes;
• taking certain medications (antiepileptics, antacids, hormonal drugs, rifampicin);
• some kidney diseases;
• increased thyroid function;
• dysfunction of the pancreas;
• decreased function of the parathyroid glands;
• rickets;
• Alzheimer's disease.

Vitamin D is one of the most important vitamins. It enters the body and is formed in the skin in the form of provitamins, which then undergo a two-stage activation. Lack of calciferols causes numerous disorders in the body. To correct such disorders, medications and dietary supplements are produced, which should be taken as prescribed and under the supervision of a physician. With long-term use, as prescribed by a doctor, laboratory monitoring of the content of vitamin D in the blood plasma is done.